| Loess is widely distributed in China and loess landslide is the serious problem. In recentyears with the implementation of the western development and the rapid rise of the westerneconomy, research and governance for the landslide has attracted much attention. Due to thespecial structural and mechanical properties of loess, it is great difficulty to study themanagement of the internal mechanism of the landslide. In order to have a betterunderstanding of the inherent law of loess landslide, in this paper firstly, it work up slopeindoor model based on loess in Yangling to explore the mechanical response andmorphological features of slope in the role of artificial rainfall by methods of digitaldeformation measurement techniques and measurement device. The FLAC3D was also usedto analyze the progress of slope’s changing deformation, shear slipping and damage due to theinstability under different water content and infiltration depth. The gradual damage progressof slope under the load at the top of slope was analyzed in the end. It could be concluded thatin this paper:(1) Before rainfall, average infiltration rate of water was86%. And then with thegrowth of Surface runoff, infiltration rate was reduced till it maintained at about40%.Through the process, the permeability of the soil was gradually reduced and certain areas ofsoil in slope became saturation.(2) In affect of rainfall, slop began to produce hill slope erosion and soil erosion withmany tension cracks and erosion ditch. When these cracks inside the slope wereinterconnected, it formed potential sliding surface. Then the further infiltration of rain wouldproduce the massive landslides, and the sliding zones were from0to1.6m below the slope.(3) The larger slope internal moisture content changes in the larger area of soilmovement is most intense. This showed that the water had a great influence on the slopefailure. The increase in moisture content caused the soil effective stress reduction andincreased the penetration of moisture to the outer slope, so that the slope was instable.(4) Under the condition of rainfalls, the soil’s water content changed by the infiltration,and the stress occurred in the part toe of slope due to the increasing water content of slope. When the water content increased to a standard value, the shear band happened from the toeof slope, and expanded gradually with the increasing water content. When the humidity inslope arrived to a certain extent, the perforative shear band formed, then the slope glided.(5) Under the condition of different infiltration rate of rainfall, the slope experienced3stages with the increasing infiltration depth. The first stage: the slope soil mass in the surfacebecome unstability rapidly, but the slope body was still stability. The second stage: with theincreasing infiltration depth, the plastic zone and surface cracks occurred at the slope interior,and the slope stability decreased substantially. The third stage: because of the waterinfiltrating into the interior, the cracks and plastic zone become an entirety, and the shear bandlinked up from toe to top, which caused the unstability damage.(6) The slope body could be obviously divided into two parts: slide mass and stablemass. When the slope failure happened, there was a apparent gradient difference indisplacement between two of them. Meanwhile, the movement of pots on the slide massincluded not only the amoeboid locomotion, but also the slipping of the slide mass itself, andthe value of former was much larger than the value of latter. |
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